Greensburg is a town in, and the parish seat of, St. Helena Parish, Louisiana, United States. The population was 629 in 2020. It is part of the Baton Rouge metropolitan statistical area.

St. Helena Parish is a parish in the U.S. state of Louisiana. At the 2020 United States census, the population was 10,920. Its seat is Greensburg. The parish was created in 1810. St. Helena Parish is part of the Baton Rouge metropolitan area.